Do food cues trigger actions more in obese than healthy-weight people?

What primary associative learning paradigm did this study use to examine the biasing effect of food cues on instrumental choice behavior?

The study utilized a computerized Pavlovian-to-instrumental transfer (PIT) task.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

Who were the primary clinical and control participants compared in this study?

The study compared 19 severely obese individuals (preparing for bariatric surgery) to 19 healthy-weight controls matched for age, education, and gender.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI

Why did the researchers specifically choose courgette and lettuce as the low-calorie food outcomes?

They were chosen because they have a similar flavor profile and are matched in palatability and low calorie content, unlike fruits which are higher in sugar and therefore more palatable.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What was the purpose of pairing each response key with one high-calorie and one low-calorie food picture during instrumental training?

This design was implemented to prevent the development of a response bias toward either key during training.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What type of associations are formed during the initial instrumental training phase of this study?

Outcome-Response (O-R) associations are formed as participants learn which key press yields which food picture.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What type of relationships do participants learn during the Pavlovian training phase?

Participants learn Stimulus-Outcome (S-O) relationships between abstract logos (Pavlovian cues) and the food pictures.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What are the two forms of response priming measured during the critical test phase?

The test measures direct response priming (triggered by food pictures via O-R associations) and indirect response priming (triggered by Pavlovian logos via S-O-R associations).

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What is the theoretical definition of a "slip of action" within the context of instrumental learning?

A slip of action occurs when an overlearned Stimulus-Response (S-R) habit triggers a behavior automatically upon stimulus presentation, even when the resulting outcome is no longer valuable.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

Why did the researchers include a slips-of-action test in this study?

It was included to investigate whether obese individuals are more prone to relying on rigid, habitual Stimulus-Response (S-R) strategies rather than goal-directed control.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

Which measures of impulsivity were included in the research design to relate obesity to cue-elicited priming?

The self-report Barratt Impulsivity Scale (BIS-11) and the task-based Stop Signal Reaction Time (SSRT) task were used.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

How did the testing environments differ between the obese and control groups?

Obese individuals were tested in a hospital room, whereas control group participants were tested either at the university or in their distraction-free homes.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What exception was made regarding the exclusion of comorbid Axis 1 psychiatric diagnoses in the obese group?

A diagnosis of depression and the concurrent use of Selective Serotonin Reuptake Inhibitors (SSRIs) were acceptable for inclusion.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What was the active training task in the Pavlovian phase?

Participants were presented with a logo at the top of the screen and had 3 seconds to click on the correct food picture out of four options in a randomized 2x2 matrix.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What was the cover story presented to participants for the computerized tasks?

They were told the 'Delicious Snack Game' involved driving along a motorway and earning points by collecting food from various stores along the way.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI

Which twelve images were presented during the critical response-priming test to assess direct and indirect priming?

The test presented 4 food pictures (direct priming), 4 Pavlovian logos (indirect priming), and 4 instrumental logos as a control condition.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

How was priming success defined on trials in the response-priming test?

A trial was defined as successful (or primed) when a participant pressed the key associated with the presented food picture or logo during training.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What was the main interactive finding regarding calorie content and group in the response-priming test?

Obese individuals showed higher priming rates for high-calorie versus low-calorie foods, whereas healthy-weight controls showed no difference between them.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI

How did healthy-weight controls perform on the response-priming task when comparing high- versus low-calorie trials?

Healthy-weight controls did not show a significant difference in response-priming rates between high- and low-calorie food outcomes.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

When comparing the two groups, how did the response-priming rates of obese individuals differ from controls for low-calorie food outcomes?

Obese individuals showed significantly reduced response-priming rates for low-calorie food outcomes compared to controls.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI

Did the obese group exhibit higher priming rates for high-calorie foods compared to the healthy-weight controls?

No, the response-priming rates for high-calorie outcomes did not differ significantly between the obese and healthy-weight groups.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI

What did the outcome-devaluation test find regarding participants' ability to select responses for valuable outcomes?

There were no significant group or calorie differences, indicating both groups could successfully identify still-valuable outcomes.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

Did the study find evidence that obese individuals are more prone to S-R habits during the slips-of-action test?

No, there was no significant difference between the obese and healthy-weight groups in their performance on the slips-of-action task.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

Did current desire for specific foods explain the response-priming differences in this study?

No, correlation analyses showed no significant relationship between food desire ratings and response-priming rates across the sample.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI

What relationship was found between response inhibition (SSRT) and performance on the slips-of-action task?

Higher impulsivity (slower SSRT) was significantly correlated with poorer performance on both the slips-of-action task and the baseline test.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

On which questionnaire and physiological/psychological measures did the obese group score higher than controls?

The obese group scored significantly higher on DEBQ external eating and reported higher levels of initial stress.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

Why did the authors run a control analysis including all 40 healthy-weight community participants?

They did so for transparency and to increase statistical power, confirming that the critical Calorie × Group interaction remained robust.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

Why did the researchers run a separate slips-of-action control analysis excluding the four depressed obese participants?

Because serotonin levels are known to affect performance on the slips-of-action task, and those four participants were taking SSRIs.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

According to the discussion, which brain region has been implicated in this response-priming effect in previous neuroimaging work?

The posterior putamen has been linked to this effect.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

How do the authors reconcile their findings with previous PIT studies showing priming is insensitive to outcome devaluation (e.g., after satiety)?

They argue that preexisting motivational relevance modifies the associative strength of O-R/S-O links formed during training, whereas post-training satiety shifts do not flexibly alter established associations.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What evidence during the training phases ruled out the idea that obese participants were simply unmotivated to perform on low-calorie trials?

Their accuracy and reaction times did not differ between high- and low-calorie outcomes during the training phases.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What clinical subgroup of obese individuals might show a higher habit propensity than the current sample?

Individuals with Binge Eating Disorder (BED) may be more prone to forming compulsive habits.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

What is the environmental implication of finding that food pictures and abstract predictive cues can trigger instrumental responses even in satiety?

It underscores the powerful, problematic influence of the modern 'obesogenic environment,' which constantly presents cues signaling unhealthy foods.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI

What limitation of the study is related to the recruitment methods and initial testing sessions?

The recruitment methods differed between groups, leading to higher reported stress in the obese group initially due to the clinical hospital setting.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

How did the visual cue of 'outcome devaluation' function during the slips-of-action test?

A red cross was superimposed over the food outcome picture to indicate it was no longer worth points.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified

Did the study find significant differences in self-reported total impulsivity (BIS-11) between the obese and healthy-weight groups?

Contrary to expectations, there was no significant difference in Barratt Impulsivity Scale (BIS) total scores between the two groups.

Source: Stimulus Control Over Action for Food in Obese versus Healthy-weight Individuals · DOI · quote verified